Amateur radio, programming, electronics and other musings

Archive for Dec, 2014

This evening I built a handheld PTT switch to use whilst portable with a headset as a footswitch isn’t always practical. I have large hands so it is still possible for me to hold the switch and type on a keyboard to log the QSO.

I decided to build one as commercial units can be expensive. I purchased a few parts and estimate the entire build cost less than Β£5. I used a Speedfit 22mm x 15mm reducer as the main unit and added a switch and a chassis mounted phono socket. To hold the phono socket in place I used a material called PolyMorph.

Polymorph is a thermoplastic polymer which melts at 62Β°C and consists of small off-white plastic granules. By heating these granules in hot water the user can easily melt the pellets to form a transparent flexible material. Once melted the opaque white pellets fuse together, become transparent and soften, allowing the user to form the plastic by hand into unique shapes. Once it cools it becomes solid and hard again.

The whole project took about 10 minutes from start to finish to complete and is very robust. Now I need to find other things to do with the PolyMorph as it was fun to use.